Solder alloys and arrangements

ABSTRACT

A solder alloy is providing, the solder alloy including zinc, aluminum, magnesium and gallium, wherein the aluminum constitutes by weight 8% to 20% of the alloy, the magnesium constitutes by weight 0.5% to 20% of the alloy and the gallium constitutes by weight 0.5% to 20% of the alloy, the rest of the alloy including zinc.

TECHNICAL FIELD

Various embodiments relate generally to solder alloys and arrangements.

BACKGROUND

Decisions have been made by the European Union to ban environmentallyhazardous substances in the near future; such decisions having been madewith regard to end-of-life vehicles ELV, indicating that hazardoussubstances such as lead should be banned. Lead-based products, e.g.lead-based solder materials used for die or semiconductor chipattachment, will be banned and removed from the market in the nearfuture.

Suitable alternative solder materials will in future be selected basedon their economic viability. The cost of suitable alternatives wouldhave to be at least comparable to that of current standard soldermaterials. Suitable alternatives will further have to meet therequirements and have the necessary properties to be used as aconnection element, e.g. a solder connection. Such alternatives wouldhave to be compatible for use on various surfaces, e.g. on lead framesor on chip back sides. They would also have to be electrically andthermally conductive, and robust and reliable enough for theirapplication, e.g. being subjected to high temperatures or varyingtemperature loads.

A further technical requirement is that the solidus temperature of thesolder material should lie above 260° C., so that the solder materialwill not melt and/or soften when subsequent processes are carried out,e.g. when soldering the printer circuit board. Further requirements ofalternative solder materials are that they meet the requirements ofductility such that solder wires may be provided from the soldermaterials.

Up till now, the semiconductor field has not had a lead-free soft solderalternative for the connection of a chip to a lead frame, or from a clipto a bond pad, which may be achieved in mass production. The technicalchallenge lies in finding a lead-free solder which has a meltingtemperature over that of the solder material used in printed circuitboards e.g. Sn—Ag—Cu systems, with typical melting temperatures of 260°C. However, the melting temperature should not be too high either, ashigh mechanical stress would have to be installed in the system to cooldown and at the same time, solidify the solder.

A lead-free solder material, apart from the melting temperaturerequirements, should have good wettability with various metallicsurfaces e.g. chip surfaces or lead frames which may be used, to ensurethat an optimal connection is provided. The solder material shouldfurther possess a certain ductility so that it can be produced andhandled in wire form. That is, the solder material in wire form shouldnot be brittle. The solder material has to withstand repetitive meltingand solidification conditions, and mechanical and thermomechanical loadswhich may be applied to the material, without succumbing to degradation.

SUMMARY

An embodiment is a solder alloy including zinc, aluminum, magnesium andgallium, wherein the aluminum constitutes by weight 8% to 20% of thealloy, the magnesium constitutes by weight 0.5% to 20% of the alloy andthe gallium constitutes by weight 0.5% to 20% of the alloy, the rest ofthe alloy including zinc.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. The drawings are not necessarilyto scale, emphasis instead generally being placed upon illustrating theprinciples of the invention. In the following description, variousembodiments of the invention are described with reference to thefollowing drawings, in which:

FIG. 1 shows a graph representing thermal conductivity (W/mK) vs.electrical conductivity (10⁶ S/m) of solder alloys;

FIG. 2 shows a phase diagram 200 of an Al—Zn alloy;

FIG. 3 shows a phase diagram 300 of a Ga—Zn alloy;

FIG. 4 shows a phase diagram 400 of a Sn—Zn alloy;

FIG. 5 shows a phase diagram 500 of a Ag—Zn alloy;

FIG. 6 shows a phase diagram 600 of a Cu—Zn alloy;

FIG. 7 shows a phase diagram 700 of a Ni—Zn alloy;

FIG. 8 shows a method for attaching a chip to a carrier according tovarious embodiments;

FIGS. 9A and 9B show an arrangement for attaching a chip to a carrieraccording to various embodiments;

FIGS. 10A to 10C show an arrangement including a solder alloy applied toa carrier according to various embodiments;

FIGS. 11A and 11B show an images of an arrangement including a solderalloy according to various embodiments;

FIGS. 12 to 14 show differential scanning calorimetry plots of a solderalloy according to various embodiments.

FIG. 15 shows a plot of experimental solder composition versustheoretical liquid phase projection for a solder alloy comprising zinc,aluminum and magnesium.

FIG. 16 shows a plot of experimental solder composition versustheoretical liquid phase projection for a solder alloy comprising zinc,aluminum and germanium.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawingsthat show, by way of illustration, specific details and embodiments inwhich the invention may be practiced. The word “exemplary” is usedherein to mean “serving as an example, instance, or illustration”. Anyembodiment or design described herein as “exemplary” is not necessarilyto be construed as preferred or advantageous over other embodiments ordesigns.

Various embodiments provide a lead-free (Pb-free) multilayer solderconnection system for electronic components, including at least one sideof a chip, a solder connection, e.g. a solder alloy, a carrier, e.g. alead frame, and a plating, e.g. a lead frame plating, formed over thecarrier.

In comparison to lead-based solders, zinc-based solder systems havebetter physical characteristics, e.g. better thermal/heat and electricalconductivity. This can be seen from FIG. 1 wherein a plot 100illustrating thermal conductivity (W/mK) versus electrical conductivity(10⁶ S/m) is shown. Pure zinc, and a zinc alloy including aluminum andgermanium are shown from measurements and from calculations to havehigher thermal conductivity and electrical conductivity compared tolead-based and tin-based solders.

FIG. 2 shows a phase diagram 200 of an Al—Zn binary alloy. With anatomic composition of 87.5% zinc and 12.5% aluminum, the Al—Zn binaryalloy may achieve a melting point of approximately 650° C.

FIG. 3 shows a phase diagram 300 of a Ga—Zn binary alloy. With an atomiccomposition of 2.5% zinc and 87.5% gallium, the Ga—Zn binary alloy mayachieve a melting point of approximately 300° C.

FIG. 4 shows a phase diagram 400 of a Sn—Zn binary alloy. Atapproximately 475° C., formed with an atomic composition of 13% zinc and87% tin, the Sn—Zn binary alloy may achieve a melting point ofapproximately 475° C.

FIG. 5 shows a phase diagram 500 of a Ag—Zn binary alloy. With an atomiccomposition of 98% zinc and 2% silver, the Ag—Zn binary alloy mayachieve a melting point of approximately 700° C.

FIG. 6 shows a phase diagram 600 of a Cu—Zn binary alloy. With an atomiccomposition of approximately 2% copper and 98% zinc, the Cu—Zn binaryalloy may achieve a melting point of approximately 425° C. Table 606shows the different phases with related alloy concentrations of theCu—Zn binary alloy.

FIG. 7 shows a phase diagram 700 of a Ni—Zn binary alloy. With an atomiccomposition of approximately 1% nickel and 99% zinc, the Ni—Zn binaryalloy may achieve a melting point of approximately 700° C. Table 706shows the different phases with related alloy concentrations of theNi—Zn binary alloy.

FIG. 8 shows a method for attaching and/or joining a chip 814 to acarrier. The method may include, in 800, selecting carrier, 802 e.g. asubstrate or a lead frame; in 804, forming plating 806, e.g. a nickelplating, over carrier 802; in 808, depositing solder alloy 810 overcarrier 802, wherein solder alloy 810 may be formed directly on plating806. In 808, depositing solder alloy 810 may be carried out according toa conventional wire bond process by melting solder alloy 810 which maybe in wire and a soft solder, over carrier 802, e.g. by forming a solderdot from solder alloy 810. Solder alloy 810 may be deposited in ribbonform or plated over carrier 802. Alternatively, solder alloy 810 may beplaced over or directly on chip 814 at wafer level, i.e. before dicingof the wafer or on chip backside 820 wherein the chip back side mayinclude chip back side metallization 816. In 812, chip 814 may beattached to carrier 802 via solder alloy 810, wherein solder alloy 810may be a connecting or joining material between chip 814 and carrier802. In 822, a further solder alloy 828 may be configured to attach aclip-on connection to a contact surface on a chip front side 830 bydepositing solder alloy 810 over one or more contact pads 818 on thechip front side 830. One or more contact wires 824 may be attached tochip 814 and/or contact pads 818 via solder alloy 828. The depositionand placement of solder alloys 810, and further solder alloy 828 may becarried out by dispensing a paste of said alloys and/or through a plasmagun.

Solder alloy 810 may be used for joining chip back side 820 to carrier802, e.g. a lead frame, even if chip 814 is not a silicon-based chip.Chip back side 820 may include a backside metallization 816 systemincluding a multilayer system or part or a variant of a multilayersystem. The multilayer system may include individual layers havingindividual functions.

The multilayer system may include contact layer 816 a for contacting toa semiconductor material, e.g. an aluminum contact layer, wherein thealuminum forms a layer having a thickness ranging from 50 nm to 1000 nm.

The multilayer system may include barrier layer 816 b, e.g. a titanium(Ti) or titanium-tungsten (TiW) barrier layer, wherein barrier layer 816b may have a thickness ranging from 50 nm to 1000 nm.

The multilayer system may include solder reaction layer 816 c, thesolder reaction layer 816 c including at least one of a group of thefollowing elements and/or alloys thereof: nickel, nickel-vanadium,silver, aluminum, gold, platinum, palladium, nickel, wherein the solderreaction layer 816 c may have a thickness ranging from 50 nm to 1000 nm.Solder reaction layer 816 c may be a “partner” layer with solder alloy810 as the thickness of solder reaction layer 816 c may be selected sothat during the solder process it does not dissolve completely in solderalloy 810.

The multilayer system may include oxidation protection layer 816 d toprevent oxidation of the solder reaction layer 816 c as solder reactionlayers 816 c including silver, gold, platinum, palladium or alloysthereof, may be prone to oxidation. Oxidation protection layer 816 d mayhave a thickness ranging from 50 nm to 1000 nm.

Substrate 802 may be formed from one of the following group ofmaterials: copper, nickel, silver or a ceramic. Plating 806 may beformed over substrate 802, e.g. substrate 802 may be a lead framewherein lead frame plating may be formed over the lead frame. Plating806 may include at least one from the following group of materials:silver, gold, nickel, platinum, palladium, vanadium, molybdenum, tin,copper, arsenic, antimony, gallium, zinc, aluminum, niobium, tantalum,phosphorus, silver, nickel, nickel phosphorus in elemental form and/orin nitride form and/or in oxide form, the at least one from said groupof materials, individually, or in combination. Plating 806 may beconfigured to be in connection with solder alloy 810.

According to various embodiments, substrate 802 may include plating 806including copper in combination with nickel and/or nickel phosphorus,wherein plating 806 may be a lead frame plating configured to be inconnection with the solder alloy. According to various embodiments,plating 806 thickness may lie in the range from about 100 nm to about 3μm.

According to various embodiments, chip 814 may include chip back side820 including at least one from the following group of materials:aluminum, titanium, nickel vanadium, silver, wherein chip back side 820may be configured to be in connection with solder alloy 810.

Solder alloy 810A according to various embodiments may include zinc,aluminum, magnesium and gallium, wherein aluminum constitutes by weight8% to 20% of alloy 810A, magnesium constitutes by weight 0.5% to 20% ofalloy 810A and gallium constitutes by weight 0.5% to 20% of alloy 810A,the rest of alloy 810A including zinc. Solder alloy 810A may berepresented by the chemical formula ZnAl_(4.5)Ga₁Mg₁. Solder alloy 810Amay be represented by the chemical formula ZnAl₁₂Ga₁Mg₁. According tovarious embodiments, solder alloy 810A may be a solder wire. Aluminummay constitute by weight 3% to 12% of alloy 810A. Magnesium mayconstitute by weight 0.5% to 4% of alloy 810A. Gallium may constitute byweight 0.5% to 4% of alloy 810A.

Solder alloy 810B according to various embodiments may include zinc,aluminum, tin and magnesium, wherein aluminum constitutes by weight 1%to 30% of alloy 810B, magnesium constitutes by weight 0.5% to 20% ofalloy 810B and tin constitutes by weight 0.5% to 6.5% of alloy 810B, therest of alloy 810B including zinc. Aluminum may constitute by weight 3%to 8% of alloy 810B. Magnesium may constitute by weight 0.5% to 4% ofalloy 810B. Tin may constitute by weight 0.5% to 4% of alloy 810B.Solder alloy 810B may be represented by the chemical formulaZnAl₄Sn₂Mg₁.

Solder alloy 810C according to various embodiments may include zinc,aluminum, germanium and gallium, wherein aluminum constitutes by weight1% to 30% of alloy 810C, germanium constitutes by weight 0.5% to 20% ofalloy 810C and gallium constitutes by weight 0.5% to 20% of alloy 810C,the rest of alloy 810C including zinc. Aluminum may constitute by weight3% to 8% of alloy 810C. Germanium may constitute by weight 0.5% to 4% ofalloy 810C. Gallium may constitute by weight 0.5% to 4% of alloy 810C.

Solder alloy 810D according to various embodiments may include zinc,aluminum and germanium, wherein aluminum constitutes by weight 1% to 20%of alloy 810D, germanium constitutes by weight 1% to 20% of alloy 810D,the rest of alloy 810D including zinc. Solder alloy 810D may berepresented by the chemical formula ZnAl₅Ge₃. Solder alloy 810D may berepresented by the chemical formula ZnAl₁₂Ge₃. Solder alloy 810D may berepresented by the chemical formula ZnAl₆Ge₃. Solder alloy may berepresented by the chemical formula ZnAl₆Ge₅. According to variousembodiments, aluminum may constitute by weight 3% to 8% of alloy 810D.According to various embodiments, germanium may constitute by weight 1%to 6% of alloy 810D.

Solder alloy 810E according to various embodiments, may include zinc,aluminum and magnesium, wherein aluminum constitutes by weight 1% to 20%of alloy 810E, magnesium constitutes by weight 1% to 20% of alloy 810E,the rest of alloy 810E including zinc. Aluminum may constitute by weight3% to 8% of alloy 810E. Magnesium may constitute by weight 0.5% to 4% ofalloy 810E.

Solder alloy 810F according to various embodiments may include zinc andtin, wherein zinc constitutes by weight 10% to 91% of alloy 810F. Solderalloy 810F may be represented by the chemical formula Zn₄₀Sn₆₀. Zinc mayconstitute by weight 10% to 15% of alloy 810F.

Solder alloy 810G according to various embodiments may include zinc andsilver, wherein zinc constitutes by weight 26% to 98% of alloy 810G.Zinc may constitute by weight 83% to 99% of alloy 810G.

Solder alloy 810H according to various embodiments may include zinc andcopper, wherein zinc constitutes by weight 80% to 98% of alloy 810H.Zinc may constitute by weight 88% to 99% of alloy 810H.

According to an embodiment, each of solder alloys 810A to 810H mayfurther include at least one from the following group of materials:silver, gold, nickel, platinum, palladium, vanadium, molybdenum, tin,copper, arsenic, antimony, gallium, zinc, aluminum, niobium, tantalum,each and/or in combination including by weight 0.001% to 10% of alloys810A to 810H.

FIG. 9A shows arrangements 930, 932 and 934 according to variousembodiments. Arrangement 930 shows solder alloy 810, e.g. solder alloy810D deposited on carrier 802, e.g. a lead frame, before attaching chip814 to carrier 802. Arrangement 932 shows an ultrasonic plot of saidarrangement 930 after attaching chip 814 using a chip attachment processto said solder alloy 810, e.g. solder alloy 810D, e.g. solder alloy 810Dhaving a chemical formula ZnAl₅Ge₃. Arrangement 934 shows an ultrasonicplot according to arrangement 932 wherein solder alloy 810 has achemical formula ZnAl₁₂Ge₃.

FIG. 9B shows arrangements 936, 938 and 940 according to variousembodiments. Arrangement 936 shows an ultrasonic plot of solder alloy810, e.g. solder alloy 810A on carrier 802, e.g. a lead frame, afterattaching chip 814 using a chip attachment process to said solder alloy810, e.g. solder alloy 810A having a chemical formula ZnAl_(4.5)Ga₁Mg₁.Arrangement 938 shows an ultrasonic plot according to arrangement 936,wherein solder alloy 810 has a chemical ZnAl₁₂Ga₁Mg₁. White colouredspots in the ultrasonic plots are indicating delamination or voidswhereas black areas are directly connected homogenous solder areas.

FIG. 10A shows an arrangement 1030 wherein solder alloy 810, e.g. solderalloy 810A, including zinc, aluminum, magnesium and gallium may beapplied to a carrier 802, e.g. a lead frame, wherein the lead frameincludes lead frame plating 806 including NiNiP. FIG. 10B shows anarrangement 1032 which shows various embodiments according toarrangement 1030 wherein lead frame plating 806 includes copper insteadof NiNiP. Solder alloy 810A shows good wetting behavior on both coppersurfaces and NiNiP surfaces of carrier 802, providing the bestperformances in terms of homogeneity of the solder alloy 810A on thesurface of lead frame plating 806. FIG. 10C shows arrangements 1034 and1036 according to various embodiments. Arrangement 1034 shows an imageof the interface between carrier 802, e.g. a lead frame, and solderalloy 810A. Arrangement 1036 shows an image of the interface betweencarrier 802, e.g. a lead frame, solder alloy 810A, and chip 814. In eachof 1034 and 1036, two chips 814 are attached to leadframe 802. The whitespots insides the chip areas 814 may be attributed to delaminations orvoids. The void rate obtained in solder alloy 810A on plating 806, e.g.lead frame plating including NiNiP is less compared to that of a plating806 including a Cu lead frame plating.

FIG. 11A shows a scanning electron microscopy (SEM) image 1130 of across section of a solder alloy 810A having a chemical formulaZnAl₁₂Ga₁Mg₁ deposited on carrier 802 e.g. a copper lead frame, andsolder alloy 810A joined to chip back side 820. Chip back side 820 mayinclude chip back side metallization 816 wherein back side metallization816 may include a Al—Ti—Ag stack. Back side metallization 816 mayinclude contact layer 816 a, e.g. aluminum contact layer; barrier layer816 b, e.g. titanium barrier layer; and solder reaction layer 816 c,e.g. silver solder reaction layer.

FIG. 11B shows image 1132 wherein marked portions of SEM image 1130 areprovided, from which Energy Dispersive X-ray Spectroscopy (EDX) data maybe extracted. Spectrum 2 1134 includes zinc, copper and aluminum.Spectrum 3 1136 includes zinc, copper, aluminum and silver. Spectrum 41138 includes zinc, copper, silver and trace amounts (less than 2%) ofaluminum. Spectrum 5 1140 includes zinc, aluminum, copper and traceamounts (less than 2%) of silver. Spectrum 6 1142 includes zinc,aluminum and trace amounts (less than 2%) of silver. The silver diffusesfrom solder reaction layer 816 c into solder alloy 810A. Gallium may bedetected between the grain boundaries, which improves the mechanicalproperties of the solder, the tensile strength of 345 MPa of solderalloy 810A having a chemical formula ZnAl₁₂Ga₁Mg₁ may be attained.Copper diffusion from the leadframe into all bright visible parts of thecross-section is detected.

FIG. 12 shows differential scanning calorimetry plots (DSC) 1230, 1236of solder alloy 810A. DSC plot 1230 shows Heat flow (W/g) 1232 versusTemperature (° C.) 1234 with respect to solder alloy 810A havingchemical formula ZnAl_(4.5)Ga₁Mg₁ according to an embodiment. Solderalloy 810A shows exothermic peaks at approximately 262° C., 340° C. and366° C. The peak representing an enthalpy of 9.0 J/g and peaktemperature 261.8° C. reflects an eutectoid reaction between zinc andaluminum. Any further peaks at higher temperatures are created byternary reactions of Zn—Al with a further alloy element of the alloy,e.g. Ga, Mg. The further peaks reflect the melting temperature range andis of importance for the setting of the process parameters. Theoccurrence of 2 or more peaks at specific positions are characteristicof a specific composition of the alloy with specific phases formedduring the manufacturing process of the wires.

DSC plot 1236 shows Heat flow (W/g) 1238 versus Temperature (° C.) 1240with respect to solder alloy 810A having chemical formula ZnAl₁₂Ga₁Mg₁according to an embodiment. Solder alloy 810A shows exothermic peaks atapproximately 273° C., 344° C. Thus, a melting point of approximately344° C. may be attained in solder alloy 810A having chemical formulaZnAl₁₂Ga₁Mg₁. The peak representing an enthalpy of 24.4 J/g and peaktemperature 272.6° C. reflects an eutectoid reaction between zinc andaluminum. Any further peaks at higher temperatures are created byternary reactions of Zn—Al with a further alloy element of the alloy,e.g. Ga, Mg.

FIG. 13 shows DSC plot 1330 showing Heat flow (W/g) 1332 versusTemperature (° C.) 1334 with respect to solder alloy 810B havingchemical formula ZnAl₄Sn₂Mg₁ according to various embodiments. Solderalloy 810B shows exothermic peaks at approximately 284° C., 336° C. and365° C. The peak representing an enthalpy of 9.0 J/g and peaktemperature 284.4° C. reflects an eutectoid reaction between zinc andaluminum. Any further peaks at higher temperatures are created byternary reactions of Zn—Al with a further alloy element of the alloy,e.g. Sn, Mg.

FIG. 14 shows differential scanning calorimetry plots (DSC) 1430, 1436of solder alloy 810D. DSC plot 1430 shows Heat flow (W/g) 1432 versusTemperature (° C.) 1434 with respect to solder alloy 810D havingchemical formula ZnAl₅Ge₃ according to various embodiments. Solder alloy810D shows exothermic peaks at approximately 283° C. and 359° C. Thepeak representing an enthalpy of 8.6 J/g and peak temperature 282.8° C.reflects an eutectoid reaction between zinc and aluminum. Any furtherpeaks at higher temperatures are created by ternary reactions of Zn—Alwith a further alloy element of the alloy, e.g. Ge.

DSC plot 1436 shows Heat flow (W/g) 1438 versus Temperature (° C.) 1440with respect to solder alloy 810D having chemical formula ZnAl₁₂Ge₃according to various embodiments. Solder alloy 810D shows exothermicpeaks at approximately 283° C., 359 C, 368° C. and 412° C. The peakrepresenting an enthalpy of 24.4 J/g and peak temperature 282.8° C.reflects an eutectoid reaction between zinc and aluminum. Any furtherpeaks at higher temperatures are created by ternary reactions of Zn—Alwith a further alloy element of the alloy, e.g. Ge.

FIG. 15 shows a plot 1500 of experimental solder composition versustheoretical liquid phase projection for a solder alloy including zinc,aluminum and magnesium. According to various embodiment, a lowestachievable melting temperature for the solder alloy of approximately350° C. may be attainable at an atomic zinc composition of betweenapproximately 91% to 96%. Axis 1532 indicates the molar fraction ofaluminum relative to zinc. Axis 1534 indicates the molar fraction ofzinc relative to magnesium. Axis 1536 indicates the molar fraction ofmagnesium relative to aluminum. The quaternary solder compositions 810B(ZnAl4Sn2Mg1) and 810A (ZnAl5Mg1Ga1) could be placed slightly above thehorizontal 400° C. line of the diagram in FIG. 15 since the lowconcentrations of tin for 810B and gallium for 810A will not changesignificantly the liquidus temperatures of the solders 810B and 810A.

FIG. 16 shows a plot 1600 of experimental solder composition versustheoretical liquid phase projection for a solder alloy including zinc,aluminum and germanium. Axis 1632 indicates the molar fraction ofaluminum relative to zinc. Axis 1634 indicates the molar fraction ofzinc relative to germanium. Axis 1636 indicates the molar fraction ofgermanium relative to aluminum. Plot 1638 shows a magnified portion ofselected portion 1640, wherein a lowest achievable melting temperaturefor the solder alloy of approximately 335° C. may be attainable at anatomic composition of 97 Zn %, 1.5 Al % and 1.5 Ge %. Solder alloy 810having the chemical formula ZnAl₁₂Ge₃ and ZnAl₅Ge₃ are points indicatedon plot 1600 and 1638. With an atomic composition of 1.6% aluminum, 80%zinc and 3.4% germanium, a four-phase intersection may be obtained. Amelting temperature of 343.42° C. may further be obtained.

In various embodiments, a solder alloy is provided. The solder alloy mayinclude zinc, aluminum, magnesium and gallium, wherein the aluminumconstitutes by weight 8% to 20% of the alloy, the magnesium constitutesby weight 0.5% to 20% of the alloy and the gallium constitutes by weight0.5% to 20% of the alloy, the rest of the alloy including zinc. Invarious embodiments, the solder alloy may be represented by the chemicalformula ZnAl_(4.5)Ga₁Mg₁. In various embodiments, the solder alloy maybe represented by the chemical formula ZnAl₁₂Ga₁Mg₁. In variousembodiments, the solder alloy may be a solder wire. In variousembodiments, the aluminum may constitute by weight 3% to 12% of thealloy. In various embodiments, the magnesium may constitute by weight0.5% to 4% of the alloy. In various embodiments, the gallium mayconstitute by weight 0.5% to 4% of the alloy. In various embodiments,the alloy may further include at least one from the following group ofmaterials: silver, gold, nickel, platinum, palladium, vanadium,molybdenum, tin, copper, arsenic, antimony, gallium, zinc, aluminum,niobium, tantalum, each and/or in combination comprising by weight0.001% to 10% of the alloy.

In various embodiments, a solder alloy is provided. The solder alloy mayinclude zinc, aluminum, tin and magnesium, wherein the aluminumconstitutes by weight 1% to 30% of the alloy, the magnesium constitutesby weight 0.5% to 20% of the alloy and the tin constitutes by weight0.5% to 6.5% of the alloy, the rest of the alloy including zinc. Invarious embodiments, the aluminum may constitute by weight 3% to 8% ofthe alloy. In various embodiments, the magnesium may constitute byweight 0.5% to 4% of the alloy. In various embodiments, the tin mayconstitute by weight 0.5% to 4% of the alloy. In various embodiments,the solder alloy may be represented by the chemical formula ZnAl₄Sn₂Mg₁.In various embodiments, the alloy may further include at least one fromthe following group of materials: silver, gold, nickel, platinum,palladium, vanadium, molybdenum, tin, copper, arsenic, antimony,gallium, zinc, aluminum, niobium, tantalum, each and/or in combinationincluding by weight 0.001% to 10% of the alloy.

In various embodiments, a solder alloy is provided. The solder alloy mayinclude zinc, aluminum, germanium and gallium, wherein the aluminumconstitutes by weight 1% to 30% of the alloy, the germanium constitutesby weight 0.5% to 20% of the alloy and the gallium constitutes by weight0.5% to 20% of the alloy, the rest of the alloy including zinc. Invarious embodiments, the aluminum may constitute by weight 3% to 8% ofthe alloy. In various embodiments, the germanium may constitute byweight 0.5% to 4% of the alloy. In various embodiments, the gallium mayconstitute by weight 0.5% to 4% of the alloy. In various embodiments,the alloy may further include at least one from the following group ofmaterials: silver, gold, nickel, platinum, palladium, vanadium,molybdenum, tin, copper, arsenic, antimony, gallium, zinc, aluminum,niobium, tantalum, each and/or in combination including by weight 0.001%to 10% of the alloy.

In various embodiments, an arrangement is provided. The arrangement mayinclude a chip; a solder alloy configured to attach the chip to a leadframe; the solder alloy including: zinc, aluminum and germanium, whereinthe aluminum constitutes by weight 1% to 20% of the alloy, the germaniumconstitutes by weight 1% to 20% of the alloy, the rest of the alloyincluding zinc. In various embodiments, the solder alloy may berepresented by the chemical formula ZnAl₅Ge₃. In various embodiments,the solder alloy may be represented by the chemical formula ZnAl₁₂Ge₃.In various embodiments, the solder alloy is represented by the chemicalformula ZnAl₆Ge₃. In various embodiments, the solder alloy may berepresented by the chemical formula ZnAl₆Ge₅. In various embodiments,the aluminum may constitute by weight 3% to 8% of the alloy. In variousembodiments, the germanium may constitute by weight 1% to 6% of thealloy. In various embodiments, the alloy may further include at leastone from the following group of materials: silver, gold, nickel,platinum, palladium, vanadium, molybdenum, tin, copper, arsenic,antimony, gallium, zinc, aluminum, niobium, tantalum, each and/or incombination including by weight 0.001% to 10% of the alloy. In variousembodiments, the lead frame may include a lead frame plating includingat least one from the following group of materials: silver, gold,nickel, platinum, palladium, vanadium, molybdenum, tin, copper, arsenic,antimony, gallium, zinc, aluminum, niobium, tantalum, phosphorus,silver, nickel, nickel phosphorus in elemental form and/or in nitrideform and/or in oxide form, the at least one from said group ofmaterials, individually, or in combination comprising the lead frameplating; wherein the lead frame plating is configured to be inconnection with the solder alloy. In various embodiments, the lead framemay include a lead frame plating including copper in combination withnickel and/or nickel phosphorus; wherein the lead frame plating isconfigured to be in connection with the solder alloy. In variousembodiments, the lead frame plating thickness lies between 100 nm to 3μm. In various embodiments, the chip may include a chip back sideincluding at least one from the following group of materials: aluminum,titanium, nickel vanadium, silver, wherein the chip back side isconfigured to be in connection with the solder alloy.

In various embodiments, an arrangement is provided. The arrangement mayinclude a chip; a solder alloy for attaching the chip to a lead frame;the solder alloy including zinc, aluminum and magnesium, wherein thealuminum constitutes by weight 1% to 20% of the alloy, the magnesiumconstitutes by weight 1% to 20% of the alloy, the rest of the alloyincluding zinc. In various embodiments, the aluminum may constitute byweight 3% to 8% of the alloy. In various embodiments, the magnesium mayconstitute by weight 0.5% to 4% of the alloy. In various embodiments,the alloy may further include at least one from the following group ofmaterials: silver, gold, nickel, platinum, palladium, vanadium,molybdenum, tin, copper, arsenic, antimony, gallium, zinc, aluminum,niobium, tantalum, each and/or in combination including by weight 0.001%to 10% of the alloy. In various embodiments, the lead frame may includea lead frame plating including at least one from the following group ofmaterials: silver, gold, nickel, platinum, palladium, vanadium,molybdenum, tin, copper, arsenic, antimony, gallium, zinc, aluminum,niobium, tantalum, phosphorus, silver, nickel, nickel phosphorus inelemental form and/or in nitride form and/or in oxide form, the at leastone from said group of materials, individually, or in combinationincluding the lead frame plating; wherein the lead frame plating isconfigured to be in connection with the solder alloy. In variousembodiments, the lead frame may include a lead frame plating includingcopper in combination with nickel and/or nickel phosphorus; wherein thelead frame plating is configured to be in connection with the solderalloy. In various embodiments, the lead frame plating thickness liesbetween 100 nm to 3 μm. In various embodiments, the chip may include achip back side including at least one from the following group ofmaterials: aluminum, titanium, nickel vanadium, silver; wherein the chipback side is configured to be in connection with the solder alloy.

In various embodiments, an arrangement is provided. The arrangement mayinclude a chip; a solder alloy configured to attach the chip to a leadframe; the solder alloy including zinc and tin, wherein the zincconstitutes by weight 10% to 91% of the alloy. In various embodiments,the solder alloy may be represented by the chemical formula Zn₄₀Sn₆₀. Invarious embodiments, the zinc may constitute by weight 10% to 15% of thealloy. In various embodiments, the alloy may further include at leastone from the following group of materials: silver, gold, nickel,platinum, palladium, vanadium, molybdenum, tin, copper, arsenic,antimony, gallium, zinc, aluminum, niobium, tantalum, each and/or incombination including by weight 0.001% to 10% of the alloy. In variousembodiments, the lead frame may include a lead frame plating includingat least one from the following group of materials: silver, gold,nickel, platinum, palladium, vanadium, molybdenum, tin, copper, arsenic,antimony, gallium, zinc, aluminum, niobium, tantalum, phosphorus,silver, nickel, nickel phosphorus in elemental form and/or in nitrideform and/or in oxide form, the at least one from said group ofmaterials, individually, or in combination including the lead frameplating; wherein the lead frame plating is configured to be inconnection with the solder alloy. In various embodiments, the lead framemay include a lead frame plating including copper in combination withnickel and/or nickel phosphorus; wherein the lead frame plating isconfigured to be in connection with the solder alloy. In variousembodiments, the lead frame plating thickness lies between 100 nm to 3μm. In various embodiments, the chip may include a chip back sideincluding at least one from the following group of materials: aluminum,titanium, nickel vanadium, silver; wherein the chip back side isconfigured to be in connection with the solder alloy.

In various embodiments, an arrangement is provided. The arrangement mayinclude a chip; a solder alloy configured to attach the chip to a leadframe; the solder alloy including zinc and silver, wherein the zincconstitutes by weight 26% to 98% of the alloy. In various embodiments,the zinc may constitute by weight 83% to 99% of the alloy. In variousembodiments, the alloy may further include at least one from thefollowing group of materials: silver, gold, nickel, platinum, palladium,vanadium, molybdenum, tin, copper, arsenic, antimony, gallium, zinc,aluminum, niobium, tantalum, each and/or in combination including byweight 0.001% to 10% of the alloy. In various embodiments, the leadframe may include a lead frame plating including at least one from thefollowing group of materials: silver, gold, nickel, platinum, palladium,vanadium, molybdenum, tin, copper, arsenic, antimony, gallium, zinc,aluminum, niobium, tantalum, phosphorus, silver, nickel, nickelphosphorus in elemental form and/or in nitride form and/or in oxideform, the at least one from said group of materials, individually, or incombination including the lead frame plating; wherein the lead frameplating is configured to be in connection with the solder alloy. Invarious embodiments, the lead frame may include a lead frame platingcomprising copper in combination with nickel and/or nickel phosphorus;wherein the lead frame plating is configured to be in connection withthe solder alloy. In various embodiments, the lead frame platingthickness lies between 100 nm to 3 μm. In various embodiments, the chipmay include a chip back side including at least one from the followinggroup of materials: aluminum, titanium, nickel vanadium, silver; whereinthe chip back side is configured to be in connection with the solderalloy.

In various embodiments, an arrangement is provided. The arrangement mayinclude a chip; a solder alloy configured to attach the chip to a leadframe; the solder alloy including zinc and copper, wherein the zincconstitutes by weight 80% to 98% of the alloy. In various embodiments,the zinc may constitute by weight 88% to 99% of the alloy. In variousembodiments, the alloy may further include at least one from thefollowing group of materials: silver, gold, nickel, platinum, palladium,vanadium, molybdenum, tin, copper, arsenic, antimony, gallium, zinc,aluminum, niobium, tantalum, each and/or in combination including byweight 0.001% to 10% of the alloy. In various embodiments, the leadframe may include a lead frame plating including at least one from thefollowing group of materials: silver, gold, nickel, platinum, palladium,vanadium, molybdenum, tin, copper, arsenic, antimony, gallium, zinc,aluminum, niobium, tantalum, phosphorus, silver, nickel, nickelphosphorus in elemental form and/or in nitride form and/or in oxideform, the at least one from said group of materials, individually, or incombination including the lead frame plating; wherein the lead frameplating is configured to be in connection with the solder alloy. Invarious embodiments, the lead frame may include a lead frame platingincluding copper in combination with nickel and/or nickel phosphorus;wherein the lead frame plating is configured to be in connection withthe solder alloy. In various embodiments, the lead frame platingthickness lies between 100 nm to 3 μm. In various embodiments, the chipmay include a chip back side including at least one from the followinggroup of materials: aluminum, titanium, nickel vanadium, silver; whereinthe chip back side is configured to be in connection with the solderalloy.

While the invention has been particularly shown and described withreference to specific embodiments, it should be understood by thoseskilled in the art that various changes in form and detail may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims. The scope of the invention is thusindicated by the appended claims and all changes which come within themeaning and range of equivalency of the claims are therefore intended tobe embraced.

What is claimed is:
 1. An arrangement comprising, a chip having a chipback side; a substrate comprising a surface; a zinc-based solder alloyconfigured to attach the chip back side to the surface of the substrate,wherein the zinc-based solder alloy consists essentially of: zinc,aluminum and germanium, wherein the aluminum constitutes by weight 1% to20% of the alloy, the germanium constitutes by weight 1% to 20% of thealloy, and zinc; wherein the surface of the substrate comprises a metallayer disposed between the substrate and the zinc-based solder alloythat provides a good wettability of the zinc-based solder alloy on thesurface of the substrate, the zinc-based solder alloy being disposedbetween the metal layer and the chip back side.
 2. The arrangementaccording to claim 1, wherein the zinc-based solder alloy is representedby a chemical formula selected from a group consisting of: ZnAl₅Ge₃;ZnAl₁₂Ge₃; ZnAl₆Ge₃; and ZnAl₆Ge₅.
 3. The arrangement according to claim1, wherein the substrate is a lead frame.
 4. The arrangement accordingto claim 1, wherein the substrate is formed by a material selected froma group of materials consisting of: copper; nickel; silver; and aceramic.
 5. The arrangement according to claim 1, wherein the metallayer comprises at least one from the following group of materials:silver, gold, nickel, platinum, palladium, vanadium, molybdenum, tin,copper, arsenic, antimony, gallium, zinc, aluminum, niobium, tantalum,phosphorus, silver, nickel, nickel phosphorus at least one of inelemental form; in nitride form; and in oxide form, the at least onefrom said group of materials, individually, or in combination.
 6. Thearrangement according to claim 1, wherein the metal layer comprises athickness in the range from about 100 nm to about 3 μm.
 7. Thearrangement according to claim 1, wherein the chip back side comprises achip back side metallization.
 8. The arrangement according to claim 7,wherein the chip back side metallization comprises at least one from thefollowing group of materials: aluminum, titanium, nickel vanadium, andsilver.
 9. The arrangement according to claim 7, wherein the chip backside metallization comprises a multilayer system.
 10. The arrangementaccording to claim 9, wherein the multilayer system comprises a contactlayer to contact to a semiconductor material of the chip back side. 11.The arrangement according to claim 10, wherein the contact layercomprises an aluminum contact layer.
 12. The arrangement according toclaim 10, wherein the contact layer has a thickness ranging from 50 nmto 1000 nm.
 13. The arrangement according to claim 9, wherein themultilayer system comprises a barrier layer.
 14. The arrangementaccording to claim 13, wherein the barrier layer comprises one of atitanium barrier layer or a titanium-tungsten barrier layer.
 15. Thearrangement according to claim 13, wherein the barrier layer has athickness ranging from 50 nm to 1000 nm.
 16. The arrangement accordingto claim 9, wherein the multilayer system comprises a solder reactionlayer.
 17. The arrangement according to claim 16, wherein the solderreaction layer comprises at least one of a group of the followingelements and/or alloys thereof: nickel, nickel-vanadium, silver,aluminum, gold, platinum, and palladium.
 18. The arrangement accordingto claim 16, wherein the solder reaction layer comprises a thicknessranging from 50 nm to 1000 nm.
 19. The arrangement according to claim16, wherein the multilayer system further comprises an oxidationprotection layer to prevent oxidation of the solder reaction layer. 20.The arrangement according to claim 19, wherein the oxidation protectionlayer comprises a thickness ranging from 50 nm to 1000 nm.
 21. Anarrangement comprising, a chip having a chip back side; a substratecomprising a surface; a zinc-based solder alloy configured to attach thechip back side to the surface of the substrate, wherein the zinc-basedsolder alloy consists essentially of: aluminum constituting by weight 1%to 20% of the alloy, germanium constituting by weight 1% to 20% of thealloy, at least one of: silver, gold, nickel, platinum, palladium,vanadium, molybdenum, tin, copper, arsenic, antimony, gallium, zinc,aluminum, niobium, or tantalum, constituting by weight 0.001% to 10% ofthe alloy, and the balance of the alloy zinc; wherein the surface of thesubstrate comprises a metal layer disposed between the substrate and thezinc-based solder alloy that provides a good wettability of thezinc-based solder alloy on the surface of the substrate, the zinc-basedsolder alloy being disposed between the metal layer and the chip backside.
 22. The arrangement according to claim 21, wherein the substrateis formed by a material selected from a group of materials consistingof: copper; nickel; silver; lead; and a ceramic.
 23. The arrangementaccording to claim 21, wherein the metal layer comprises at least onefrom the following group of materials: silver, gold, nickel, platinum,palladium, vanadium, molybdenum, tin, copper, arsenic, antimony,gallium, zinc, aluminum, niobium, tantalum, phosphorus, silver, nickel,nickel phosphorus at least one of in elemental form; in nitride form;and in oxide form, the at least one from said group of materials,individually, or in combination.
 24. The arrangement according to claim21, wherein the chip back side comprises a chip back side metallization.25. The arrangement according to claim 24, wherein the chip back sidemetallization comprises a multilayer system.